The actual flow rate of the pump is less than the normal flow rate. Possible reasons for this phenomenon.
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The actual flow rate of the pump is less than the normal flow rate. The possible reason for this phenomenon is that the production capacity expansion requires the pump flow rate to be 20m3/h. The normal flow rate of the original pump used in production is 21m3/h, and the rated flow rate is 27m3/h. It turns out that this pump is often used at 7~8m3/h, but now I want to use it to transport 20m3/h material. Logically, this pump should still be usable, but some people said that they did experiments and found that this pump can only deliver a maximum flow of 10m3/h. I would like to ask everyone to discuss why this is the case? The material inlet diameter is DN100, the outlet diameter is DN100, the inlet length is 50 meters, the outlet is 500 meters, and the pump lift is 100 meters.
This post was last edited by zhgl982 on 2010-2-9 17:01 This has a lot to do with the pipeline settings. If the outlet pipeline resistance of the pump is large, the flow rate of the pump will not reach the rated flow rate. The outlet line diameter is also a design mistake as is the inlet line diameter.
1. The pump will undergo a factory operation test before leaving the factory, and there will be a test report. If the report is qualified before leaving the factory, it can only be because the pipeline settings are inappropriate. 2. Is the design and processing of the pump itself incorrect?
But some people said that they did experiments and found that this pump can only produce a maximum flow rate of 10m3/h. You need to ask this person why the flow cannot increase when the flow reaches 10m3/h.: A: Will noise, vibration and cavitation occur if the flow rate is further increased? B: The outlet valve has been opened to the maximum, and all valves on the pipeline have been 100% open? C: Will the current automatically trip when it exceeds the protection value? If it is situation A, then the resistance of the inlet pipeline is too great and the pressure at the inlet needs to be increased. ； If it is situation B, then the resistance of the outlet pipeline is too great and the resistance of the pipeline is needed. ； If it is working condition C, the motor power is too small and needs to be replaced with a larger power motor. ； If none of the above is the case, you have to check the factory test data and do some tests, such as completely closing the outlet valve to see if the pressure at the pump outlet and the current value of the motor are consistent with the factory data, and send the results here for discussion.
“But some people said that they did experiments and found that this pump can only produce a maximum flow of 10m3/h. Is this statement confirmed? If it is verified that it can only reach 10m3/h, then there are probably several reasons for the small flow rate: 1. The pump itself, pump processing problems, and no testing at the factory; 2. After long use, the pump rotating parts are worn, causing the gap to expand; 3. The oil viscosity increases Add, or the number of filter mesh is too large 4. The reason for the motor speed is clearly speaking. The rated flow of the pump is 27m3/h, and it is often used in the range of 7~8m3/h. I personally think it is a problem of selection, which consumes electric energy and causes a waste of resources. ； Furthermore, the basic parameters of the pump were not verified before use, which is irresponsible!
Judging from the data you provided, the main reason should be that the inlet pipe of the pump is too long, reaching 50 meters. For centrifugal pumps, the shorter the inlet pipe, the better.
API stipulates that pump manufacturers conduct performance tests before leaving the factory and indicate the maximum flow rate and minimum continuous flow rate on the curve. used within this range. Vibration, ultrasound and other indicators comply with corresponding standards. However, pump manufacturers rarely do this test. I'll tell you a way: Change the flow rate by adjusting the outlet valve. Observe the ammeter and measure the actual allowable minimum and maximum flow. At the same time, measure the vibration and noise and the bearing temperature to meet the requirements. Ensure that the rated value of the motor is not exceeded.
The physical properties of the medium change such as density, annual etc. . .